Daytime sleepiness in patients with obstructive sleep apnea and associated comorbidities

Obstructive sleep apnea (OSA) is characterized by recurrent upper-airway collapse during sleep, leading to ineffective respiratory efforts, intermittent hypoxia, and sleep fragmentation. Patients with OSA often have comorbid conditions. Excessive daytime sleepiness (EDS), defined as an inability to remain awake during the day, is common among patients with OSA; however, its perception may vary with comorbidities that affect autonomic and neuroendocrine regulation.

We reviewed studies examining the prevalence and clinical impact of EDS in patients with OSA and its main comorbidities, published between January 2000 and September 2025, and identified through Medline.

EDS is highly prevalent in patients with OSA and arterial hypertension, cardiac arrhythmias, cerebrovascular comorbidities (particularly in those with thalamic or pontine lesions), diabetes mellitus, metabolic syndrome, asthma, chronic kidney disease, and cancer. By contrast, EDS appears less prevalent in patients with heart failure, treated cerebrovascular and neurodegenerative disease (particularly in those receiving levodopa, selective serotonin reuptake inhibitors, or bromocriptine), and chronic obstructive pulmonary disease (COPD).In conclusion, in patients with OSA, EDS is perceived differently depending on comorbidity. Consequently, EDS assessment should follow a personalized, multidimensional approach that recognizes its clinical relevance while accounting for variability across comorbid conditions.